1. Field of the Invention
The present invention relates to a fuel injection apparatus for an internal combustion engine, which injects fuel from an upstream side of an inlet valve towards the inlet valve, and to a fuel injection method of an internal combustion engine, and a fuel injection valve.
2. Description of the Related Art
In Japanese Unexamined Patent Publication No. 2001-295738, there is disclosed a fuel injection apparatus for an internal combustion engine in which an extension pipe is provided on a tip end portion of a fuel injection valve, and fuel is injected towards the inlet valve via this extension pipe.
Furthermore, in Japanese Unexamined Patent Publication No. 2004-225598 there is disclosed a fuel injection valve where, in a engine furnished with two inlet valves in respective cylinders, a flow amount of fuel injected from a fuel injection valve is a maximum value at a position displaced from a central portion of a valve head of one inlet valve towards the other inlet valve.
According to this fuel injection valve, attachment of fuel to the combustion chamber wall is suppressed, and hence the discharge amount of hydrocarbons HC from the engine can be reduced.
Furthermore, in Japanese Unexamined Patent Publication No. 2005-120994, there is disclosed an internal combustion engine provided with a rectifying plate which partitions the internal path of the inlet pipe into upper and lower separate paths and also a butterfly valve which controls the inlet flow of air to the lower path of the inlet pipe extending below the rectifying plate.
When the butterfly valve is closed, air flows only in the flow path on the upper side of the inlet pipe, and as a result a strong tumble flow is produced inside the combustion chamber.
Incidentally, at the time of starting the engine, since the temperature of the inlet valve is low, the vaporization rate of the fuel attached to the valve head of the inlet valve is low, and the film thickness of the liquid fuel attached to the valve head of the inlet valve is thick. Therefore, at the time of starting, a large amount of fuel flows into the combustion chamber in the liquid state, so that the discharge amount of hydrocarbons HC from the engine becomes great.
Furthermore, in the above manner, in the case where a rectifying plate is provided in order to intensify the tumble flow, the air movement in the inlet pipe changes. However up to now, the fuel spray with respect to the change in the air movement has not been optimized.